The overall objective of the study is to examine cross-sectionally drug use patterns and determinants along the United States/Mexico border, (the San Diego/Tijuana area). Specifically, the research plan seeks to address the impact of migration and cross-border mobility on drug using patterns. The extent of migration, (first, second or third generation) and bi-cultural and bi-national identity roles and their impact of drug patterns will be examined. The proposed pilot research will be both exploratory and comparative, and will seek to investigate epidemiological similarities and differences in the mechanisms, distal and proximal, leading to initiation, progression and maintenance of drug use behaviors in both sides of the border. The study will be conducted with a sample of four hundred subjects, age 18 to 25 years. An equal number of participants of each nationality will be enrolled to facilitate comparisons. Within each national group, an equal number of female and male subjects will be recruited. To the extent that pilot data allow it, the proposed research seeks to further advance the field of cross-cultural comparisons of drug use by examining ethnic and national differences in the relationship between drug use and cultural identity. We expect that pilot data from this research will serve to guide in the future larger multi-focused, culturally appropriate assessments and interventions that address the growing, interdependent, global impact of drug use and abuse. [unreadable] [unreadable]